Theory, Design and Tests on a Prototype Module of a Compact ...

iv INTRODUCTION
In the state of art of the linear accelerator design, many aspects
are involved: the theoretical design, the numerical design <strong>and</strong> the experimental
verification, namely the radiofrequency measurement. In
this thesis all the aspects are covered, sometimes with less details <strong>and</strong>
sometimes with more. This is due to the own nature of the work. It
was developed during the effective design <strong>and</strong> construction of the module,
up to all the practical details a construction needs, <strong>and</strong> for time
reasons, sometimes the more known classical techniques were preferred.
Nevertheless, several scientific ideas have come out in sight of an industrial
productions of LIBO. First, the possibility to apply engineering
criteria to the design; then, the possibility to have automatic measurement
which should not need high qualified human contribution. All
these points are stressed where it is the case.
Finally, we would spend some words about the agencies involved in
this project. First the TERA Foundation, directed by Prof. U. Amaldi,
where the first ideas were born. Then, the CERN in Geneva, where
the most part of the construction <strong>and</strong> measurement has been made <strong>and</strong>
where the project team was used to gather (the author has been spent
almost the half part of his PhD at CERN). Next, INFN Sez. di Milano
e Napoli who gave money <strong>and</strong> people to work on this project, <strong>and</strong> last
but not least, the Dipartimento di Ingegneria Elettrica in Naples that
has a good tradition in accelerator development <strong>and</strong> where the author
has the privilege of doing his PhD.
In the first chapter a short introduction to the hadrontherapy is
presented with a description of the main medical centers in the world
that use hadrontherapy.
In the second chapter, we deal with an introduction to the linear
accelerator, with the definition of the main parameters involved <strong>and</strong> the
characteristics of coupled cavities. Particular emphasis is paid to the
side coupled structure. In this chapter it is also presented LIBO structure
with the radiofrequency, beam dynamic <strong>and</strong> mechanical aspects
stressed as well.
In the third chapter the effective radiofrequency design of a side
coupled linac with a top-down methodology is shown. All the aspects
are covered: from the first numbers involved, up to the definition of the
single cavities details, while in the fourth chapter a circuit model is
presented which has the aim to give the sensitivity of the main parameters
to mechanical tolerances. Numerical results are shown as well.
In the last chapter a detailed description of radiofrequency measurement
on the prototypes is illustrated. Some innovative approaches
are presented on the measurement of coupled cavities <strong>and</strong> a flux diagram
of both mechanical <strong>and</strong> measurement procedure is commented.